tree e6a8fc1cd34dec568883cd62102e1e626d9241d9
parent 1b5ed5e1f1315e37380e55102f58bcae3344d2a7
author Tejun Heo <htejun@gmail.com> 1131609125 +0100
committer Jens Axboe <axboe@nelson.home.kernel.dk> 1131789366 +0100

[BLOCK] Implement elv_drain_elevator for improved switch error detection

This patch adds request_queue->nr_sorted which keeps the number of
requests in the iosched and implement elv_drain_elevator which
performs forced dispatching.  elv_drain_elevator checks whether
iosched actually dispatches all requests it has and prints error
message if it doesn't.  As buggy forced dispatching can result in
wrong barrier operations, I think this extra check is worthwhile.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>